Adam, Comparing the speed of DSP chips by simple numbers is not terribly useful. The C62/C67 families are especially awkward to compare to other DSPs because of their VLIW instruction format. I try to compare these parts by considering how the instructions can be used for simple DSP algorithms. The most common computation is a convolution. This is simply MACs (multiply accumulates). The C6 and C62 compute in a similar manner for this function. In a convolution only 4 of the 8 computation units do useful computations. This would give you 600 MFLOPS compared to 1200 MIPS (TI's rating using all 8 computation units). I count each MAC as a single instruction as it is in most other DSPs. This gives you 300 MIPS vs. TIs rating. TI is really overrating these chips, very knowingly. When you are doing computations that access memory, the other four computation units are calculating addresses and accessing memory. These are functions that every other DSP chip does without counting them as MIPs. So at 150 MHz, the C67 and C62 chips are roughly equivalent to simpler chips running with dual accumulators at 150 MIPs. The C5510 will surpass that when it is out later this year. At 01:10 PM 1/18/01, you wrote: >Hi, > > we're considering a C6711 DSK. The Ti Site >(http://focus.ti.com/docs/tool/toolfolder.jhtml? >PartNumber=TMDS320006711) states, > >"Operating at 150 MHz, the 'C6711 delivers an impressive 1200 MIPS >and 600 MFLOPs for only U.S. $22* (1K units). " > >So Im lookin in the PDF file for the processor (sprs073d) and I see - > >" >Fixed-Point: TMS320C6211 > 150-, 167-MHz Clock Rates > 6.7-, 6-ns Instruction Cycle Time > 1200, 1333 MIPS > >Floating-Point: TMS320C6711 > 100-, 150-MHz Clock Rates > 10-, 6.7-ns Instruction Cycle Time > 600, 900 MFLOPS > 512K-Bit (64K-Byte) L2 Unified Mapped >" > >Can someone explain whether this thing does 600/900 Mflops or >1200/1333 Mips, or both, which would be okay by me. > > thanks, > Adam Rick Collins Arius - A Signal Processing Solutions Company Specializing in DSP and FPGA design Arius http://www.arius.com 4 King Ave 301-682-7772 Voice Frederick, MD 21701-3110 301-682-7666 FAX |